Taphozous hildegardeae, Thomas, 1909

Bonaccorso, Frank, 2019, Emballonuridae, Handbook of the Mammals of the World – Volume 9 Bats, Barcelona: Lynx Edicions, pp. 350-373 : 352-353

5 . Hildegarde’s Tomb Bat

Taphozous hildegardeae

French: Taphien de Hildegarde / German: Hildegarde-Grabfledermaus I Spanish: Tafozo de Hildegarde

Other common names: White-wingedTomb Bat

Taxonomy. Taphozous hildegardeaeThomas, 1909 , “

Rabai , 700 ’ [= 213 m],” Mombasa District , Kenya .

Taphozous hildegardeae is in the subgenus Taphozous . Some authorities question locality records attributable to central Kenya because. hildegardeae is otherwise known only from coastal distribution and habitats; however, these inland records coincide with coastal vegetation along the Tana River, possibly offering suitable habitat Monotypic.

Distribution. E Africa along coast of SE Kenya and NE Tanzania (from Lower Tana River S to Dar es Salaam), also on Pemba and Unguja Is (Zanzibar Archipelago); recorded in C Kenya, but verification of museum vouchers and additional fieldwork could clarify distribution there.

Descriptive notes. Head-body 79-82 mm, tail 25-29 mm, ear 13-22 mm, hindfoot 11— 18 mm, forearm 63-66 mm; weight 24-36 g (largest weights are for males with heavy fat deposits). Hairs on dorsum of Hildegarde’s Tomb Bat are tricolored, with pale brown above white bases and chocolate-brown tips; venter is white, with lightly frosted brown scattered tips. Exposed skin on limbs and other body parts is brown. Dorsal wing surfaces and uropatagium are brown, but distal part of wing membranes is white. Sparse fur on dorsal and ventral sides of flight membranes is white. Profile of head is concave. Both sexes have radio-metacarpal sacs. Although some sources state that glandular gular pouches are absent, others have observed these glands on mature males. Breeding age males have distinct black beards, covering undersides of their throats.

Habitat. Tropical dry forests in very restricted coastal areas from sea level to elevations of C.214 m. Hildegarde’s Tomb Bat also might occur further inland in gallery forests along the Tana River.

Food and Feeding. Hildegarde’s Tomb Bat eats species of Orthoptera and Lepidoptera .

Breeding. In coastal Kenya, reproductive cycle ofHildegarde’s Tomb Bat closely corresponds to regional seasonality in rainfall. Males have pronounced bimodal cycles of fat deposition, corresponding to relative insect abundance during dual rainy seasons in Kenya. During active courtship and copulation in the first dry season of the year when moth abundance is lowest, males deplete body fat; fat accumulation in males is greatest in the long rainy season in Kenya. Females do not put on appreciable fat deposits, and even near-term pregnant females do not reach large seasonal body weights of males. A secondary peak in body weight and development of male sexual glands are associated with “short rains” in October-December. Second rainy season apparently does not result in reproduction but appears to allow maintenance of year-round harems that might reflect a vestigial polyestrous reproductive cycle.

Activity patterns. Hildegard’s Tomb Bat is nocturnal and uses coral sea caves as roosts along the coast. It emerges from day roosts well after dark.

Movements, Home range and Social organization. Hildegard’s Tomb Bat is polygynous, and males maintain roost territories to defend their female harems. In some larger harems, multiple males defend a group’s roosting site. Distance between harems is slightly greater than striking distance of the forearm. Adult males defend harems from intruders by wing flicking, vocalizations, scent marking, postural changes, and aggressive attacks. Males identify females as harem members by anal-genital sniffing. Males also mark harem females by pressing throat glands over females’ dorsum and mark themselves by rubbing their folded wings and forearms over throat glands. Bachelor males andjuveniles roost separately from harems. Colonies of hundreds to c.1000 individuals occur in caves, suggesting that local foraging movements occur at considerable distances from roosting sites. Hildegard’s Tomb Bats often share lit parts of caves with African Sheath-tailed Bats ( Coleura afra ). The cimicid bug Loxaspis miranda and the bat fly Brachytarsina aUuaudi have been identified as common ectoparasites in the larger colonies of Hildegard’s Tomb Bats.

Status and Conservation. Classified as Vulnerable on The IUCNRed List. Extent of occurrence of Hildegard’s Tomb Bat is less than 20,000 km2, its distribution is severely fragmented, and there is continuing decline in extent and quality of its forest habitat. It has been recorded from fewer than ten coastal localities. No distribution-wide population estimates are available, but surveys in Kenya and Tanzania in 1988 documented more than 130, 300, and 1000 individuals in three caves. Hildegard’s Tomb Bat likely is declining due to loss of habitat in coastal dry forests and disturbance of cave sites. Updated surveys of cave populations are needed to reassess it conservation status.

Bibliography. ACR (2017), Colket & Wilson (1998), Harrison (1962), Kock (1974), McWilliam (1988b), Mickleburgh, Hutson & Bergmans (2008b), Usinger (1966).

Figures

On following pages: 4. Hamilton'sTomb Bat [Taphozous hamiltoni); 5. Hildegarde'sTomb Bat (Taphozous hildegardeae}; 6. Long-winged Sheath-tailed Bat (Taphozous longimanus); 7. Black-beardedTomb Bat (Taphozous melanopogoh); 8. Theobald'sTomb Bat (Taphozous theobaldi); 9. Indonesian Tomb Bat (Taphozous achates); 10. Arnhem Sheath-tailed Bat (Taphozous kapalgensis}; 11. Coastal Sheath-tailed Bat (Taphozous australis}; 12. Common Sheath-tailed Bat (Taphozous georgianus); 13. Hill's Sheath-tailed Bat (Taphozous hilli); 14. Troughton's Sheath-tailed Bat (Taphozous troughtoni); 15. Pel's Pouched Bat (Saccolaimus peli); 16. Bare-rumped Sheathtailed Bat (Saccolaimus saccolaimus); 17. Papuan Sheath-tailed Bat (Saccolaimus mixtus); 18. Yellow-bellied Sheath-tailed Bat (Saccolaimus flaviventris).

Distribution. E Africa along coast of SE Kenya and NE Tanzania (from Lower Tana River S to Dar es Salaam), also on Pemba and Unguja Is (Zanzibar Archipelago); recorded in C Kenya, but verification of museum vouchers and additional fieldwork could clarify distribution there.